1. Field of the Invention
The disclosure relates to an organic light emitting diode, and a panel and a display using the same. More specifically, the present invention relates to a white organic light emitting diode, and a panel and a display using the same.
2. Description of Related Art
Organic light-emitting diodes (OLED) are light in weight and ultra-thin in thickness, and also have advantages of high brightness, rapid response, wide viewing angles, no backlight requirement, low manufacturing cost and flexibility. Hence, OLEDs have great potential to apply on display panels of various electronic devices such as panels of cell phones, vehicles and MP3 players.
OLEDs can be classified into red OLEDs, blue OLEDs, green OLEDs and white OLEDs based on colours of emitting light. In the white OLEDs, white light is obtained by using several fluorescent or phosphor materials with different colours at the same time. Conventional white OLEDs are usually tandem OLEDs with plural light emitting units connecting in series by connecting layers, which have high light emitting efficiency and brightness.
However, the equivalent optical thickness of the conventional OLEDs is substantially the same as the cavity length in which visible light wavelength forming destructive interference or constructive interference, so a problem that the intensity of one primary color is enhanced and that of the other primary color is decreased may be occurred. In addition, even though OLEDs are developed in which the distance for forming constructive interference can correspond with the wavelength differences between three primary colors, a blue shift may be occurred in resonance wavelengths and thereby a color shift is occurred. Furthermore, when a light emitting layer and an electrode is too close, the energy of the light emitting from the light emitting layer may be coupled, and the coupled energy enters into a surface plasmon mode. In this case, the light emitting efficiency may be decreased.
Hence, it is desirable to provide an OLED to prevent the problem of color shifts and improve the light emitting efficiency thereof.